The invention relates to a storage arrangement for machine tools, comprising at least two storage shelves arranged vertically one above the other and in each case having a multiplicity of tool and/or workpiece retainers, the tool or workpiece retainers being arranged in a circle, and a movable gripping arm which is rotatably arranged about an axis through the center of the circle formed by the retainers and which furthermore is arranged so as to be movable in the vertical direction with respect to the storage shelves and which furthermore is arranged so as to be movable horizontally and radially from the circle center.
For the machining of workpieces made of metal, plastic or other materials, programmable “machining centers” monitored by the computer are being increasingly used. A machining center essentially comprises a table on which a workpiece can be held in a defined position during the machining. “Pallets” or work carriers serve for the defined fastening of the workpieces. For the machining of the workpiece, a wide variety of tools are used, for example for drilling, milling, broaching, sawing, cutting or planing. Depending on the form of the initial material and depending on the form of the desired finished product, the workpiece can be machined from several sides. The workpieces and tools can be moved linearly and/or rotationally with respect to one another. Three to six axes are defined for the movement: X, Y and Z for the linear movements and A, B and C for the rotary movements. In order to achieve efficient series production, a multiplicity of machining steps with various tools on a number of workpieces are programmed in advance for a relatively long time segment. The tools also become worn due to the machining. A multiplicity of tool changes are therefore necessary. For the neat grouping of the tools and of the unmachined and machined workpieces, storage arrangements are provided which are operated by program-controlled manipulators or industrial robots. The “chip-to-chip” tool change time, i.e. the time which the machine requires for the changing of the tool, is to be as short as possible for a high efficiency. The preparation time, i.e. the time during which the machine is continuously in readiness for the further tools, likewise contributes decisively to the increase in efficiency. The energy consumption during the tool or workpiece change is to be kept as low as possible.
WO 2003072300 A1 discloses an arrangement for changing and storing tools for a machining center. A multiplicity of tool retainers are formed on the inner circumference of a ring-segment-shaped frame. A rotatable arm has two gripping devices, the first gripping device serving to store the tools and the second gripping device serving to withdraw the tools from storage. The gripping devices have an embossment or a bevel which interacts with a finger on the tool retainer. This achieves the effect that the tool is stored and withdrawn from storage with a defined orientation.
The object of the invention is to specify a storage arrangement for machine tools which permits machining which is as efficient as possible and is as favorable as possible in terms of energy.